SA seems to have an online mapping system (as do most Australian states). The SA one is clunky and extremely slow although seems to work. It does say it is only 'open' from 8am to 8pm (SA time) so not sure if it will work outside of those hours or not - it seems too though.
http://maps.sa.gov.au/plb/ - The layers button has useful stuff you can turn on/off etc.
The aerial imagery on this site is a lot better than that of Google maps also.
Pictures below:
Wynarka lot numbers
View attachment 79845
There seems to be a lot of vacant lots to the south legally subdivided given the size of the town (or lack thereof).
Survey plan numbers
View attachment 79846
Street numbers - seems incomplete/Council records are probably poor/non existent
View attachment 79847
Websleuths is lowering the quality of the images. I can upload to an external image site later if of use, or you can use the link above to see the same stuff etc.
I hadn't really looked at aerial imagery of the town previously - it puts it in perspective as to just how small the place really is.